If you are not using a Variax with VDI, hook it up in line just as you would any other fx. Meaning guitar-> screamer->Pod->amp.
I've used a ton of screamers in my day and find the pod screamer to be very very good! If yours is that much better, then you are a very lucky person! But I bet you can't control the drive with your expression pedal, the output with the exp2 and the treble with the tone knob on your guitar (assuming you are using a Variax)

I found my old two pedals noisy as, probably failing components in them.

You might also try bringing the outs from the pedals to the loop return on the HD and place your FX Loop where ever you like. It might be that some noise and tone suck is running the pedals straight to the HD's Pre Amp when really the pedals are like a pre amp.